On Monday the network starts “AMTV,” a six-hour block for music and advertising experimentation. From 3 to 9 a.m. Monday through Thursday, it will show music videos, news, interviews and performances, harking back to the network’s origins as a 24-hour home for music videos.

Now, of course, the network is more synonymous with unrealistic reality shows like “The Hills” than with music. Over the years the network, a unit of Viacom, has relegated music videos to its less popular digital channels and intermissions between shows.